The river round is the final round of betting in a game of Texas Hold'em. At the beginning of this round the fith and final card is placed face up in the community cards. This is also an expensive round as bets are usually at the table high limit.
This is the round when the fourth community card is placed face up. In this round betting is usually called the expensive round as in this round betting is made at the table high-limit.
The official All Africa Poker site (for more information), or keep up to date on the happenings by visiting the All Africa Poker Blog which is updated as it happens.
Poker Terminology 
